Simultaneously molded bridge stop construction for sliding clasp fasteners



June 13, 1950 E. E. DAY

SIMULTANEOUSLY MOLDED BRIDGE STOP CONSTRUCTION FOR SLIDING CLASP FASTENERS 2 Sheets-Sheet 1 Filed March 1.3, 1946 Izwezzioa EveWeZi/ E'. D

I ufilioa aaeys June 13, 1950 E 5 D 2,511,397

SIMULTANEOUSLY MOLDED BRIDGE STOP CONSTRUCTION FOR SLIDING CLASP FASTENERS Filed March 13, 1946 2 Sheets-Sheet 2 Izweeziofl: EvewefifE D0133, z ijwwz 4M 8 W fliiowneys stringers.

iatented June 13, 1950 siMUtrAN QIuIsI-a Motnrint eitoe $16. 3 CONSTRUCTION FOR SLIDING- CLASP FASTENERS Everett E. my, Aiidover, ass, 'assigiio'r to The *Bolta Company, Lawrence, Mil/85;, a corporationof -Massachusetts iippiieationivmreii 13, 1946, 'sriaiNo. 654,100

'4 Claims.

This invention relates to bridge top stone for sliding clasb fasteners having a pair of stringers provided complementary "series of interlocking elements aidarit e d tobe moved into and out of engagement bi a. sheer and in'whfich the upper ends of the stringers are eo'n'nected together by a staple brother means commonly "known in the aitas a bridge. 'Oneo f'the objects of the invention is to provide a top stop construction itadapted to keep the edges of the stringer above t e bridge we stop to ether While holding them apart below the top stopin such barallel'i'sin as t6 facilitate "the movement of the slider u on the "complementar interlocking i'neiii'bers of the Another object 'of the inverition'is to provide a. construction of this character in which the to stop members and the inter-locking elements of thestringers'ca-n simultaneously be molded upon the stringers, thereby eliminating all problems of location of the top sto'p and the respective interlocking elements and providing 'a relatively inexpensive construction.

A further object of the invention is to provide a strong bridge top stop which 'wh'e'n molded upon theStfiiigersWill impregnate the material thereof and "adhere "thereto with 'g-ieater firmness.

Afiirthe'r object of the invention is to provide a construction in Whieh the'top stops and the in- -tr1be1inge1ements of both stringers can be $1- mi-llta'lhediis'ly molded by injection (if thermoplastic material rendered 'fl iid by heat and ingjtedonder bressurethroug h a'riinner and gates l'eeir'lir'i'g to the respective interlocking elements *iifid top stop members, whereby the material of the-runner and gates'can'after cooling be broken awa and regrotind anduseda'g'ain.

A urthe'r objectof the invention is to provide a bridge top stop having comblementary stop members each extending lengthwise of the edge "or 'thest'rin'ger having anchoring means embrac- "ing' "and fixedly "secured to the edges of the 'respeetive stringers and having end portions 15mvi'ded with complementary interlocking means so tonstructed'as to hold the toii sto mmbe'r-s in "silch anginarly diverging relation to each Other as pro'iaerly to space the interlocking members of the"stringerfor free sliding engagement by the slider.

V 'A -fiirthe'robject of 'the-invention'is to provide top *s'toio members "of the character above descri'bedbf un orm "thickness symmetrically embracing theedg'es of the respective stringers "and having at" the tide interlocking means edabted edge relation and having means for preventing disengagement when thus "assembled.

These 'and other'bbject's and features of the invention will more fully appear from the following description and the accompanying drawings and will be 'ioejrti'cularly pointed out in the claims.

A preferred embodiment of the invention is illustrated in the ac66m )anyi-ng drawings, in

which:

Fig. 1 is apian view of =a "giaii' of stringers havin}; complementary series of interlocking elemerits and top stop membersan'chored upon the stringers with the top "stop members assembled and bound suchsymmetrieai diverging relation to each-other as to position the respective series of interlocking elements in properly spaced relation Fig. 2 is a perspective View of a stop member for one of the stri'iigers, the beaded edge of the stringer to which it is applied being omitted for the sake of clearness ofillnstration;

Fig. 3 is an inner edge viiiv'o f the stop member shown in Figs; 1 and -2 taneously'casting ormolding the interlocking elements and t'o stop-'members'upon both stringers; and

Fig. Bisa plan'viewo fjthe lower die complemm-m to that shown in Fig. 7, illustrating the runner and gates to the mold leading therefrom to the interlocking elements and the top stop members.

The invention as illustrated in Fig. 1 'comprises a pair ofstri'ngers I and 2 having respectively beade'd ed'ge's 3 and 4,'the*stringer I having secur'e cl'to it ase'rie's of interlocking elements 5 of thermoplastic material 'molded or die cast upon the s'tring'e'rhaving leg portions 6 embracing the beaded edge of'the'string'er and impregnatingth'e fabric thereof. The stringer 2 has "similarly secured to it a series of complementary interlocking elements 1. The beaded edges of each of the stringers also has molded or die cast upon it top stop members having 'in'terneng'aging upper end [portions so constrncted that-the-sto'p members di "verge'symmetricallyin such manner as to hold to be asseiribled' in mtere'rigagment in dleetw 'the -inte'r16kirig l m ii s "t respective stringers in properly spaced relation to enable the slider to run easily upon them.

The stop members which are secured to the respective stringers may be provided with any sort of interlocking means adapted to retain them in properly diverging directions. In the particular embodiment of the invention illustrated herein the stop member 8, which is similarly cast or molded upon the stringer I with an anchoring portion embracing the edge of the stringer, is of a construction illustrated in Figs. 2 and 3, and comprises a body of general rectangular form of uniform thickness the upper end portion of the inner edge 9 of which is provided with an angularly slabbed portion [9, at the upper side of the medial plane of the stop member in which the edge of the stringer is located. A recess l I is provided which extends inwardly from the edge 9 and slabbed-ofl portion and upon the other side of the plane of the stringer recesses l2 and I3 are provided which likewise extend inwardly respectively from the slabbed-off and side portions 9 leaving a projection M. A transverse groove l5 extends across said upper portion and a complementary groove It extends across the lower portion which as shown merges into the recesses IS. The stop member ll, which is similarly cast or molded upon the stringer 2 with an anchoring portion embracing the edge of the stringer, is of generally rectangular form illustrated in Figs. 4 and 5 and provided with a slabbed-ofi end l8 complementar to the slabbedofi end ill of the stop member 8. Upon one side of the plane of the stringer the stop member I1 is provided with an end recess l9 complementary to the projection ll] of the stop member 8 and a projection 2i) complementary to the recess l2 of the stop member 8. The under side of the stop member I! is provided with a recess 2| adapted to receive the projection 14 of the stop member 8. The stop member I! is also provided with an external transverse groove 22 which when the stop members 8 and I1 are interlocked in edge to edge relation is in alinement with the groove I5 in the stop member 8. The opposite side of the stop member I7 is likewise provided with a groove in alinement with the groove 22, the grooves 15 and 22 of the respective stop members when assembled registering and being adapted to receive a metal binding band 23 as illustrated in Figs. 1 and 6 adapted firmly to hold the interlocked end portions of the stop members firmly in position and to prevent lateral separation thereof. The binding member 23 preferabl is of a thickness equal to the depth of the groove and may be in the form of a staple having its ends bent toward each other in such manner as to form a substantially continuous rectangular ring, as shown in Fig. 6.

The manner in which the interlocking elements of the respective stringers and the respective stop members thereof may be simultaneously cast is shown in Figs. 7 and 8 in which the upper and lower dies for thus molding or casting the same is shown. The lower die member shown in Fig. 8 comprises a plate having longitudinally extending parallel shallow areas 24 and 25 to receive the respective stringer tapes and longitudinal grooves 26 and 21 to receive the beaded edges of the stringers. The lower mold is provided with a series of suitably spaced cavities 28 for the respective interlocking elements and cavities 29 and 30 for the stop members. The mold is provided intermediate of these cavities with a longitudipal y extending runner 3i and gates 32 extend- 4 ing therefrom lead to the cavities of the respective interlocking elements. Similar gates 33 and 34 lead from the runner 3| to the cavities 29 and 30 for the stop members. The upper die illustrated in Fig. 7 is provided with longitudinally extending shallow areas 35 and 36 complementary to the shallow areas 24 and 25 respectively to receive the respective stringers. The upper mold shown in Fig. 7 likewise is provided with longitudinally extending stringer-receiving grooves 31 and 38 complementary to the stringerreceiving grooves 26 and 21 with series of suitably spaced cavities 39 for the interlocking elements registering with the cavities 28 of the lower series. The upper mold section is provided with 2. preferably central sprue hole 40 through which the flowing thermoplastic material may be introduced by pressure when the upper mold is superimposed upon the lower mold and held in proper position relatively thereto by suitable studs 4| projecting downwardly from the upper mold and firmly seated in sockets 32 in the lower mold.

By reason of this mold construction all of the interlocking elements of both stringers and the stop members of both stringers can be simultaneously cast or molded by supplying material preferably under suitable pressure through the sprue hole 40 to the runner and from the runner to the respective cavities of the mold. The mold may thereafter be cooled sufficientl to harden the thermoplastic material, the mold members separated and both stringers with the interlocking elements and stop members molded thereon removed from the mold together with the material of the runner and that of the gates of the mold. The runner and gates may then be readily broken away and reground and any roughness upon the heads of the interlocking elements and upon the stop members ground off and the ground sections polished to produce a completed pair of stringers having the interlocking elements and stop members fixedly and rigidly secured thereto. The stop members may then be readily assembled and firmly bound together by the strap 23 in the manner above described. 7

It will be obvious that by thus simultaneously casting or molding the interlocking members and the stop members upon the respective stringers the production of such members of a sliding clasp fastener can be expeditiously performed in a minimum of time, without wastag of material, and at a minimum of expense.

It will be understood that the particular embodiment of the invention shown and described herein is of an illustrative character and is not restrictive and that various modifications in the form of interlocking elements and stop members and the manner of securing the stop members together may be made within the spirit and scope of the following claims.

Having thus described the invention, what is claimed as new, and desired to be secured b Letters Patent, is:

1. A top stop for sliding clasp fasteners having a pair of stringers provided with complementary series of interlocking elements adapted to be moved into and out of interengagement by 'a slider, said top stop comprising complementary stop members of thermoplastic material extending lengthwis of the upper'end portions of the respective stringers and embracing and impregnating the edge portions thereof and provided respectively in upper adjacent end portions with complementary interlocking projections and recesses, positioning the stop members in such downwardly diverging v-shaped relation as to space the stringers and the interlocking elements thereof sufficiently apart to facilitate the movement of the slider thereon, and means for permanently securing the interlocking stop members firmly in interlocked position.

2. A top stop for sliding clasp fasteners havin a pair of stringers provided with complementary series of interlocking elements adapted to be moved into and out of interengagement by a slider, said top stop comprising complementary stop members of thermoplastic material extending lengthwise of th upper end portions of the respective stringers and embracing and impregnating the edge portions thereof and provided respectively in upper adjacent end portions with complementary interlocking projections and recesses, positioning the stop members in such downwardly diverging V-shaped relation as to space the stringers and the interlocking elements thereof sufficiently apart to facilitate the movement of the slider thereon, said assembled stop members having complementary alined transverse grooves surrounding the interengaged portions thereof, and a band fitting in said groove embracing said members and fixedly securing them in assembled position.

3. A top stop for sliding clasp fasteners having a pair of stringers provided with complementary series of interlocking elements adapted to be moved into and out of interengagement by a slider, said top stop comprising complementary stop members of thermoplastic material extending lengthwise of the upper end portions of the respective stringers symmetrically embracing and impregnating the edge portion thereof and provided respectively at their end portions with complementary projections and recesses of difierent contour on opposit sides of the plane of said stringers which when engaged in edge to edge relation will prevent lateral relative displacement of said stop members and position said stop members in such downwardl diverging V-shaped relation to each other as to space the stringers and interlooking elements thereof sufficiently apart to facilitate the movement of the slider thereon, and means for permanently securing said interengaged projections and recesses firmly in interlocked position.

4. A top stop sliding clasp fastener construction comprising a pair of stringers having simultaneously molded thereon complementary series of cooperating interengaging elements of thermoplastic material accurately spaced for interengagement by a slider movable longitudinally thereon and cooperating stop members of thermo plastic material embracing the edges of the respective stringers and impregnating the adjacent edge portions thereof, said stop members extending lengthwise of the upper end portions of the respective stringers and provided at their upper inner edge portions with complementary projections and recesses of different contour on opposite sides of the plane of the stringers adapted when interengaged to prevent lateral relative displacement thereof and so constructed as to position the stop members in such downwardl diverging V-shaped relation as to space the stringers and interlocking elements thereof sufiiciently apart to facilitate the movement of the slider thereon, said assembled stop members having complementary alined transvers grooves extending transversely around the interengaged portions thereof, and a band fitting said groove permanently securing the interengaged portions of the stop members firmly in interlocked position.

EVERETT E. DAY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,830,079 Whitney Nov. 3, 1931 2,146,714 Austin Apr. 20, 1943 2,190,609 Farnstrom Feb. 13, 1940 2,316,787 Gould Apr. 20, 1943 

